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A fun, free platform for learning modern cryptography

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Learn By Doing

Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.

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Level Up

Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?

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Fresh Challenges

We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.

New Challenges
GLP420 (HackTM CTF) CTF Archive 0
unrandom DSA (HackTM CTF) CTF Archive 0
kaitenzushi (HackTM CTF) CTF Archive 0
d-phi-enc (HackTM CTF) CTF Archive 0
broken oracle (HackTM CTF) CTF Archive 0
Weekly Top Users
#1 xeji 1935
#2 aparker314159 1590
#3 ashishbazad 1560
#4 nhatdang1901 1545
#5 BlobbyBob 1540
Recent Solves
Salty nnewram
Manyprime nnewram
Finding Flags kunkun
Square Eyes nnewram
Diffie-Hellman Starter 5 gratigo
Recent Solutions
ECB CBC WTF crypto619 0
Modular Binomials mohammad_otoom 0
Chinese Remainder Theorem mohammad_otoom 0
Legendre Symbol mohammad_otoom 0
Quadratic Residues mohammad_otoom 0

Level Up

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